NAYPYITAW (BLOOMBERG) - An Australian adviser to Myanmar's detained civilian leader, Ms Aung San Suu Kyi, is being investigated by the authorities under two separate charges, the junta's main spokesman said on Tuesday (March 23).

Mr Sean Turnell, who was detained shortly after the military takeover of the country in a coup on Feb 1, is being investigated for violations of Myanmar's immigration and official secrets acts, Brigadier-General Zaw Min Tun said in a briefing.

If found guilty, he could face several years in prison.

"We have allowed Sean Turnell to speak to his family on the phone twice, and will allow him more," he said.

The investigation comes as Myanmar's military faces sanctions from the US and its allies and the country has been embroiled in deadly protests.

More than 260 people have been killed since the coup, according to the Assistance Association for Political Prisoners.

On Monday, the US handed down its latest round of targeted sanctions against individuals and entities in Myanmar including two army divisions.

Earlier in the day, the European Union imposed restrictive measures of its own on 11 individuals responsible for the military coup, including army chief Min Aung Hlaing.

Last week, the military regime piled more charges on ousted leader Suu Kyi as it seeks to justify the coup and ensure she stays behind bars.

She was charged with violating an anti-corruption law, adding to four other charges the junta previously filed.

During Tuesday's briefing, Brig-Gen Zaw Min Tun threatened journalists not to communicate with the parallel government set up by overthrown members of Ms Suu Kyi's National League for Democracy, saying they would face legal action for doing so.

He also said that the junta has no intention of restoring full Internet connectivity in Myanmar any time soon amid persisting and widespread cuts since the coup.

"People are using the mobile Internet to instigate destructive acts," he said.